The overall objective of the research program is to demonstrate and characterize the lymphoblast-associated antigens on the surface of normal lymphocytes transformed by continuous culture in vitro or following incubation with mitogen. The occurrence of similar determinants on normal and leukemic lymphoblasts will be tested. Finally, the reactivity of leukemic lymphocytes to lymphoblast-associated antigens will be determined. The goals of the current year of study were (1) to determine the contribution of EB viral determinants to the capacity of lymphoblasts to stimulate autologous lymphocyte transformation and (2) to raise antisera to lymphoblast-associated determinants.